Then you provide your child with the appropriate level of support and reassurance.

That's the responsive part.

Simple, and very powerful.

For years, researchers have noticed that that sensitive, responsive parenting is linked with better cognitive outcomes for children. For example, infants learn language more rapidly when caregivers respond promptly and contingently to what babies do (Tamis-Lamonda et al 2014).

But there may be important health benefits, too. Research suggests that sensitive, responsive parenting can protect children from chronic disease, premature aging, and toxic stress.

Take, for example, kids living in neighborhoods blighted by poverty and crime.

These kids experience atypical fluctuations of the stress hormone cortisol, putting them at increased risk for a variety of metabolic conditions, including obesity, cardiovascular disease, and diabetes. Elevated cortisol levels may also "turn on" genes that cause inflammation.

When University of British Columbia psychologists Gregory Miller and Edith Chen tested adolescents for biochemical markers of inflammation, they found that kids of lower socioeconomic status were more likely to develop a “pro-inflammatory phenotype."

Having such a phenotype increases your risk of developing inflammatory diseases like atherosclerosis, autoimmune disorders, and cancer (Miller and Chen 2007).

Can parents protect kids from the physiological effects of stress?

The idea fits with our everyday observations. Sensitive,
responsive parents make children feel safe. They make kids less
suspicious of other people, and therefore more relaxed. Secure, relaxed children experience fewer spikes of cortisol, and when they do get stressed, they recover more quickly.

In addition, by teaching their kids how to regulate
their own emotions, parents help children develop effective self-soothing mechanisms. Kids learn how to cope, even when their caregivers aren't around. Together, these factors should help protect kids from the physiological wear-and-tear caused by chronic stressors (Repetti et al 2002; Chen et al 2011).

So Chen and Miller sought to test the idea by inquiring into the early life experiences of people who grew up poor.

In
one study, they asked 53 healthy young adults about their family relationships. Study volunteers
who reported feelings of greater warmth toward their mothers showed fewer signs of
systemic inflammation (Chen et al 2011).

In another study, the researchers explored the effects of parental
warmth and sensitivity on the development of metabolic syndrome, a cluster of medical conditions that includes central obesity, high blood pressure, and insulin resistance. The researchers asked over 1200 middle-aged Americans questions about their parents. Questions like:

How much did your parent understand your problems and worries?

How much time and attention did s/he give you when you needed it?

Then the researchers examined participants for symptoms of metabolic syndrome.

As expected, people who grew up in low socioeconomic status (SES) households were more likely to have these symptoms. But about 45% of the people with low SES childhoods were symptom-free. And these symptomless people were more likely to have had nurturing mothers.

Among kids with the most nurturing mothers, there was no correlation between SES and poor health status.

To put this in perspective, the researchers also tested the effects of being upwardly mobile. If you were born relatively poor, but achieved higher SES as an adult, did you enjoy better health?

Surprisingly, the answer was no. Not when it came to symptoms of metabolic syndrome. The researchers couldn’t detect any difference between people who stayed poor and people who moved up the socioeconomic ladder.

Is this proof that sensitive, responsive parenting has a lasting impact on health?

No. These studies don’t control for genetic factors. Perhaps nurturing parents are more likely to carry genes that confer better health.

Perhaps, too, the results are skewed by the participants’ inaccurate reports of their parents’ behavior.

And what about fathers? Miller and his colleagues didn’t find evidence of any effect for nurturing dads. Just moms. Is that because the fathers in this study were less involved with childcare? Future studies are needed to rule out alternative explanations.

But in the meantime, there is other evidence to consider. For instance, experiments on nonhuman animals suggest that family interactions have a profound impact on health.

When researchers have cross-fostered rat pups -- assigned them to be raised by adoptive mothers -- they have found strong evidence for the power of affectionate care. Rats raised by highly responsive mothers show less stress reactivity as adults (Francis et al 1999; Meaney 2001).

And in experiments on zebra finches, investigators found that a bird's lifespan depended on the temperament of its companions. Anxious, easily "stressed out" finches lived longer when they when they were paired with calmer, more resilient companions (Pat Monaghan et al 2012).

There are also intriguing observational studies tracking human children over the short-term.

In addition, research on babies exposed to prenatal stress found that 7-month-old infants showed signs of better emotional regulation if their mothers had exposed them to lots of physical affection (Sharp et al 2012).

Follow-up studies confirm the effect lasts into the toddler years, and researchers have connected the phenomenon to epigenetics, or long-term alterations of DNA function (Sharp et al 2015; Pickles et al 2016).

Early life stress can silence genes that help regulate an individual's stress response system. But tactile affection seems to reverse the process (Murgatroyd et al 2016).

If true, scientists may have uncovered a key mechanism for parental responsiveness and affection to impact health. But regardless of the mechanisms, researchers are amassing an increasingly impressive case for the health benefits of responsive, sensitive parenting.